package graph.mst;

class StackX {
	private final int SIZE = 20;
	private int[] st;
	private int top;

	public StackX() // constructor
	{
		st = new int[SIZE]; // make array
		top = -1;
	}

	public void push(int j) // put item on stack
	{
		st[++top] = j;
	}

	public int pop() // take item off stack
	{
		return st[top--];
	}

	public int peek() // peek at top of stack
	{
		return st[top];
	}

	public boolean isEmpty() // true if nothing on stack
	{
		return (top == -1);
	}
}